溶胶—凝胶法制备CZTS薄膜太阳电池及其光伏性能的研究

发布时间：2018-03-28 23:26

本文选题：薄膜太阳电池　切入点：溶胶-凝胶法　出处：《河北大学》2017年硕士论文

【摘要】：近几年,铜铟镓硒(CIGS)等化合物薄膜太阳电池由于可柔性化、易大面积生产且光电转换效率高等优点,受到了广泛的关注。但由于CIGS材料中的III族元素铟与镓地球中储量少、价格昂贵,限制其未来的大规模应用。铜锌锡硫(CZTS)材料用比较廉价且储量丰富的锌与锡元素替代铟与镓,从而大大降低成本,更适用于大规模应用。CZTS具有与太阳光谱相匹配的禁带宽度(1.5 eV)和在可见光范围内超过104 cm-1的吸收系数,理论的光电转换效率超过30%,是一种良好的吸收层材料。CZTS薄膜的制备有基于真空与非真空的多种方法,但真空方法的制备成本较高,而由联氨溶液法制备的CZTS电池获得了目前的最高效率12.6%。本论文主要采用一种低成本、高产出并且无毒环保的溶胶-凝胶法来制备高性能的CZTS薄膜,化学溶液法制备的氧化锌纳米线作为窗口层,纳米粒子沉积法制备的硫化镉作为缓冲层,制备了倒置结构的CZTS薄膜电池。垂直排列的纳米阵列更有利于太阳电池中载流子的传输,从而大大降低电子空穴对的复合、提高电池的光电转换效率。并通过X射线衍射(XRD)、拉曼光谱(Raman)、紫外可见光吸收(Abs)、扫描电子显微镜(SEM)、IV测试等测试手段研究了薄膜的结构、纯度、带隙、形貌以及电池器件的光伏性能;同样采用溶胶-凝胶的方法在衬底Mo上旋涂制备CZTS前驱体薄膜,并通过在硫的气氛中退火得到高质量结晶的CZTS薄膜,由于高温下CZTS易分解而产生二次相硫化锌(ZnS),为了去除CZTS薄膜表面的二次相Zn S,选用一定浓度的盐酸溶液进行刻蚀处理。通过XRD、Raman、SEM、X射线荧光光谱分析仪(XRF)等测试手段表征了薄膜与器件的性能,主要获得了如下结果:使用溶胶-凝胶法制备CZTS吸收层,化学水溶液法制备ZnO纳米线,纳米粒子沉积法制备CdS缓冲层,最终得到结构为FTO/ZnO NWs@CdS/CZTS/Ag的倒置结构的CZTS薄膜太阳电池,通过优化CZTS吸收层的退火温度,CdS缓冲层的厚度和氧化锌的形貌等参数,最终得到转换效率高达2.27%的倒置结构CZTS薄膜太阳电池。使用溶胶-凝胶法在Mo衬底上制备前驱体CZTS薄膜,在硫的气氛中进行退火以得到高质量的结晶薄膜,在退火过程中施加一定的气压,抑制了锡元素的挥发并得到结晶性更好的薄膜;并且通过对不同退火温度下制备的薄膜及电池器件进行表征测试,随着硫化温度的升高薄膜结晶质量在增加,晶粒尺寸变大,提高了CZTS薄膜太阳电池的开路电压与短路电流,所制备的太阳电池的转换效率随着硫化温度的升高先增加后降低,在温度为580℃时光电转换效率达到最大值2.74%。最后,通过采用325nm波长的激发激光对样品进行Raman测试得到紫外拉曼光谱,发现了二元杂相ZnS的特征拉曼峰,检测出CZTS薄膜表面存在ZnS杂质,为了去除ZnS相,采用盐酸溶液对硫化后的CZTS薄膜进行刻蚀,通过对盐酸溶液的浓度与刻蚀时间的优化,得到在5%的盐酸溶液中刻蚀5min时电池器件的光电性能最佳,最高效率为4.72%。
[Abstract]:In recent years, copper indium gallium selenide (CIGS) thin film solar cells due to compounds such as flexible, easy production of large area and high photoelectric conversion efficiency, has been widely concerned. But because the III elements in CIGS earth indium and gallium in the material less expensive, limit its large-scale application in the future the copper zinc tin sulfide (CZTS) zinc and tin indium and gallium instead of cheap and abundant reserves of materials, thereby greatly reducing the cost and more suitable for large-scale application of.CZTS band gap is matched with the solar spectrum (1.5 eV) and the absorption coefficient in the visible light range of more than 104 cm-1, the photoelectric the theoretical conversion efficiency of more than 30%, is a good material of the absorption layer of.CZTS thin films prepared by a variety of methods of vacuum and non vacuum based on vacuum method, but the preparation cost is higher, while the CZTS battery is prepared by hydrazine solution obtained at the most High efficiency 12.6%. this paper mainly uses a low cost, high output and non-toxic sol-gel method to CZTS thin films with high performance, chemical solution prepared by Zinc Oxide nanowires as the window layer, deposition of cadmium sulfide nanoparticles as a buffer layer of CZTS thin film solar cell inverted structure was prepared. Nano the vertical alignment of the array more suitable for transmission carrier in solar cell, thereby greatly reducing the recombination of electron hole pairs, improve photoelectric conversion efficiency of the battery. And through X ray diffraction (XRD), Raman spectroscopy (Raman), ultraviolet visible light absorption (Abs), scanning electron microscopy (SEM), IV test methods to study the structure of the films, purity, bandgap, morphology and photovoltaic properties of solar cell devices; the same by the sol-gel method on the substrate of Mo spinning CZTS precursor thin films prepared by coating, and sulfur in the atmosphere back The fire to get high quality CZTS thin film crystal, due to the high temperature CZTS can decompose and produce two phase zinc sulfide (ZnS), to the surface of CZTS film two phase Zn removal of S hydrochloric acid solution with certain concentration of etching process. Through XRD, Raman, SEM, X ray fluorescence spectrum analyzer (XRF) were conducted to characterize the properties of thin films and devices, the main results obtained were as follows: the preparation of CZTS absorption layer using sol-gel method, chemical solution preparation of ZnO nanowires, nanoparticles deposition of CdS buffer layer, finally get the structure of CZTS thin film solar cell FTO/ZnO NWs@ CdS/CZTS/Ag inverted structure, through the optimization of CZTS the annealing temperature absorption layer, the thickness of CdS buffer layer and Zinc Oxide morphology parameters, finally get the inverted structure of CZTS thin film solar cell conversion efficiency as high as 2.27%. The sol-gel method used in Mo substrate preparation of precursor CZ TS films were annealed in sulfur atmosphere to obtain crystalline films of high quality, exert some pressure in the annealing process, inhibit the volatilization of tin and crystalline better; and through the different annealing temperature for film and battery device were characterized with the rise of temperature, curing the crystal quality of the films increased, the grain size and improve the open circuit voltage and short circuit current of CZTS thin film solar cells, the conversion efficiency of the solar cell prepared with increasing curing temperature first increased and then decreased, at the temperature of 580 DEG time electricity conversion efficiency reaches the maximum value of 2.74%. at last, through the laser excitation of Raman test the samples obtained by UV Raman spectroscopy using a wavelength of 325nm, found that the characteristic Raman peak of two yuan a phase of ZnS, to detect the presence of ZnS impurity CZTS film surface, in order to remove the ZnS phase with salt The sulfurized CZTS film was etched by acid solution. By optimizing the concentration and etching time of HCl solution, it was obtained that when the 5min was etched in 5% HCl solution, the photoelectric performance of the battery device was the best and the highest efficiency was 4.72%..

【学位授予单位】：河北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM914.42

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